Resistance for auto ignition coils



Feb. 28, 1928. 1,661,619

I c. H. THORDARSON RESISTANCE FOR AUTO IGNITION COILS Filed Au 28, 1925 @L I gy y J iii.

Patented Feb. 212, 1925i.

UNITED STATES CHESTER H. TEQRDARSON, OF CHICAGO, ILLINOIS.

RESISTANCE FOR AUTO IGNITION COILS.

Application filed August 28, 1925. Serial No. 53,055.

The main objects of this invention are to provide a simple and reliable resistance unit which s especially adapted for use on the ignition systems used on internal combustion engines; to provide a construction which will stand a heavy overload without danr age; to provide a unit which is convenient to install; to provide a construction which will maintain operatively perfect insulation; to provide a unit which can be assembled without loss through breakage of material; and to provide a unit having a fixed and reliable mechanical and electrical connection to the terminals of the resistance element without use of solder.

An illustrative embodiment of this invention is shown in H accompanying drawings, in which:"

Figure 1 is a plan view of device, showing principally the top connecting plate.

Fig. 2 is a side view of the resistance unit assembled.

Fig. 3 is a sectional view of the resistance unit on the line 33 of Fig. 4, and showing the details of the electrical connection between the resistance element and the bottom conne ting plate.

Fig. l is a sectional view of the complete unit on the line 44- of Fig.

in order to maintain the resistance element 1 in a tired position, it is wound on a hollow cylinder or sleeve 2 of insulating material. such as porcelain or the like. On the outer surface of the cylinder are formed grooves 3 similar to a screw thread in which grooves the resistance element 1 is placed, forming a helix. The hollow insulating cylindcr Q is mounted on a metal post at. The metal post is divided into two sections 5 and (3. The lower section 5 is designed for screw thread attacluncnt at 7, to the standard ignition coil terminal. A shoulder 8 integral with lower section 5 serves to hold the cyl inder 2 in place. The lower section 5 is cut so as to form a recess 9 and a substantial lip or process 10, and the upper core section 6 has a similar recess and process with clearance, forming complementary interlocking surfaces. The clearance 10 is filled with insulating material 10 such as heavy asbestos cloth. "When the clearance is properly filled, the post section forms a symmetrical post with the two ends 5 and 6 insulated from each other yet firmly interlocked by the process-recess construction and held in this relationship by the surrounding sleeve 2, to prevent pulling the ends away from each other. The upper core section 6 has an integral threaded stud or shank 11.

The bottom connecting plate 12 is provided with a circular aperture which tits the post st. The top connecting plate 13 has an aperture to pass the threaded stud 11 of the upper core section 6. There is provided a lock nutlet which bears on the top plate 13 and holds the entire assembly together, and a knurled thumb nut 15 for clamping a conductor wire.

The plates 12 and 13 are each provided with three loops 16 struck out from the wing portions thereof for receiving and securing the ends of the resistance element 1. The plates 12 and 13 are also each provided with a lug 16 located so as to lit in slot 17 formed in the ends of thecylinder 2 and holding the plates from axial rotation when assembled.

Assembly of the unit comprises filling the recess-process clearance between the core sections 5 and 6 with insulating material. the result being a substantial American binding post with ends insulated from each other. The bottom connecting plate 12 slides over the core 4 resting on the shoulder 7. Then the hollow cylinder or sleeve 2 is slipped over the core and positioned so that the slot 17 engages the lug 16 on the lower connecting plate 12. The top plate 13 is then placed in position with its lug 16 fitted in the slot 17 in that end of the cylinder 2, and the lock nut 14 is screwed down on the stud 11 so as to bear against the plate 13. The post body is purposely made shorter than the cylinder so that when the nut 14: is screwed down to engage the top plate 13, then the top plate acts as a spring washer, holding under spring tension both the post and cylinder in their predetermined positions. The resistance element is then wound in the grooves 3 and the ends threaded through the three loops 16 in the connecting plates, after which said loops are pressed back toward the plate to hold the ends of the resistance element in a mechanical lock which gives positive electrical connection without the use of solder.

Although but one specific embodiment of this invention has been herein shown and described, it will be understood that numerous details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

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I claim: I l. A resistance umt comprising a post cut into two sections, a process and a recess on post body, an insulating member surround.

ing the body of said post, a resilient plate holding said insulating members on said assembled post, a resistance element, and means for establishing electrical contact between said resistance element and said post sections.

3. A resistance unitcomprising a post, a

shoulder on said post, insulation between the ends of said post, an insnlatingcylinder surrounding said post and supported by said shoulder, connecting plates provided with loops threaded on said post, one of said connecting plates acting as a spring Washer holding said cylinder, a spiral groove on said cylinder, a resistance element wound in said groove and mechanical means for bold ing the terminals of said element in electrical contact in said loops.

4. A resistance unit comprising a binding post in two sections, each of said sections being provided with complementary interlocking surfaces, insulating material 'sepameters rating said sections, an insulated sleeve surrounding said sections adapted to hold said sections in interlocked relationship and a resistance element carried bysaid sleeve, said element having electrical connection with each of said post sections.

5. A resistance unit comprising a binding post cut into two sections, a process and a recess on each section, with clearance between said process and recess, insulating material filling said clearance and forming a symmetrical post body, connecting plates coacting with said post sections, lugs and loops on said connecting plates, a hollow insulating cylinder surrounding said post body, and having grooves formed in the exterior surface thereof, said cylinder being provided with notches in the ends thereof for receiving said lugs, said insulating cylinder being held under spring tension by pressure between said connecting plates, a resistance element wound in said grooves and having its ends passed through said loops, said loops being adapted through compression to establish electrical contact between said resistance element and said connecting plates.

6. A resistance element comprising a pair of core members arranged in axial alinement and each having complementary interlocking surfaces, insulation between said members. an insulating sleeve surrounding said members and holding them in interlocked relationship and a resistance element supported on said sleeve and having electrical connection with each of said core members.

Signed at Ghicagothis 25th day of August, 1925.

CHESTER H. THORDARSON.

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